Liquid separator



N wE

INVENTORS JOSEPH FERNANDES FRANK B.

LANE

ATTORNEY RAYMOND s. DEGROOTE HE/l? 1970 J. FERNANDES ET AL LIQUID SEPARATOR Filed Feb. 20, 1968 United States Patent U.S. Cl. 55-430 Claims ABSTRACT OF THE DISCLOSURE A separator removing entrained finely divided liquid particles from a flowing gaseous fluid, utilizing a principle of interposed cascade vanes to induce coalescence under conditions of minimum pressure drop and providing a circumferential cartridge to absorb and transport agglomerated droplets.

This invention relates to water separators, and particularly to devices of this class required to remove entrained liquid from flowing air under conditions of low pressure drop, as for example in aircraft air conditioning systems.

Water separators of the related prior art conventionally make use of coalescers, usually in the form of screens made of fabric or fibrous material through which the flowing air is directed. The finely divided liquid particles in the air stream are blown clear of the coalescing screens as droplets, are allowed to collect on surfaces of the separator and are drained therefrom. Coalescing screens may inhibit a proper flow of air, particularly under atmospheric conditions promoting icing at the screens. Provision must be made for by-passing clogged screens. The result is operation under conditions of relatively high pressure drop and structure of substantial complication.

An object of the present invention is to introduce a generally new mode of operation in water separators in which the air stream is subjected to radial turning moments bringing about coalescing through the exercise of centrifugal and allied effects.

Another object of the invention is to eliminate the need for coalescing screens and like devices in water separators, it being an attendant object in this connection to provide a water separator of high efficiency and low pressure drop having no need for coalescing screens.

A further object of the invention is to utilize planned radial acceleration in a flowing air stream in conjunction with circumferential water absorbing and transport media to achieve a high degree of separation under favorable operating conditions.

A still further object of the invention is to obviate use of pressure relief valves.

Still another object of the invention is to provide for planned radial acceleration through the use of interposed cascade vanes.

Other objects and structural details of the invention will appear from the following description, when read in connection with the accompanying drawing, wherein:

FIG. 1 is a view in longitudinal section of a Water separator in accordance with a first illustrated form of the invention;

FIG. 2 is a view in cross section, taken substantially along the line 22 of FIG. 1;

FIG. 3 is a view in cross section taken substantially along the line 3-3 of FIG. 1; and

FIG. 4 is a fragmentary view in longitudinal section of a water separator in accordance with a second illustrated form of the invention.

Referring to the drawing, a water separator in accordance with the illustrative embodiment of FIG. 1 comprises an open ended tubular shell 10 one end of 3,490,209 Patented Jan. 20, 1970 which receives a circular support 11. The latter provides longitudinally spaced apart bearings to engage a short length of tube 12. The support 11 positions tube 12 concentrically of the shell 10, the tube being of substantially less diameter than the shell. An inner end of the tube 12 terminates within the shell in a relatively sharp edged surface 13. The other end of the tube projects outside the shell and terminates in an expanded flange 14 serving as an adapter by which the tube 12 may be connected in a line flowing a gaseous fluid under pressure. At the opposite end of the shell 10 is a tube 15 similar to and aligned with the tube 12. An outer end of the tube 15 is expanded as a flange 16 to be connected in the fluid flowing system. The tube 15 with its flange 16 comprises part of a sub-assembly, further including a support 17 like the support 11 and a ring 18 in which support 17 is positioned. A sleeve 19 serves as an extension of the shell 10 and receives ring 18 therein, the sub-assembly of which the ring is a part being held within sleeve 19 by a retainer ring 21. In a brazing or like process, shell 10 is united with sleeve 19 and with support 11, the latter being joined in like manner to the tube 12. The sub-assembly comprised of parts 15, 16, 17 and 18 may similarly be joined together and inserted within and held in sleeve 19 as a unit by ring 21.

The separator is connected in a fluid flowing system, as for example in an air stream emanating from an en gine compressor or the like, in a manner to have tube 12 serve as the separator inlet and tube 15 to serve as the separator outlet. Thus, compressor air, entraining finely divided moisture particles from the atmosphere is suitably ducted to flange 14 and is introduced through tube 12 to the interior of the shell 10. Conditioned air, from which moisture has been removed in a manner to be described, exits through tube 15 and is conducted to a place of use.

Axially disposed in the shell 10, intermediate inlet tube 12 and outlet tube 15, is a shaft 22. Mounted to that end of the shaft 22 facing inlet tube 12 is a multibladed air flow guide 23. Held to the shaft by means including a nut 24. Secured to the opposite end of the shaft 22, through respective hubs 25 and 26 are other air flow guide members 27 and 28. The member 23 is made of relatively light weight yet stiff material, as for example sheet metal. It is initially formed as a disc, is lanced along a plurality of radial lines to form a circumferential series of individual blade elements and the blade elements are then turned to a desired pitch or degree of angularity. The member 23 is made to correspond approximately to the inside diameter of the shell 10. In the assembly of parts, the tips of the blade elements contact the inner wall of the shell in a manner centrally to position shaft 22 and its mounted member 23. The blade tips may be brazed to the shell wall to restrain the blades from axial displacement and from rotary turning motion. The air flow control members 27 and 28 may be constructed like the member 23 or may be made of a molded plastic or like material. They have, in any event, respective circumferential blades 31 and 32 respectively twisted to a desired pitch or degree of angularity relative to the shaft 22 and shell axis. In accordance with a feature of the invention, the pitch of blades 29 is. different from the pitch of blades 31 and 32, the latter being substantially the same but members 27 and 28 being angularly displaced relatively to one another in a rotary sense so that corresponding edges of the blades 31 and 32 overlap. Further, the pitch of blades 29 is less than that of blades 27 and 28, that is, the blades 29 are turned at an angle to impose a lesser turning moment to impinging air than are the blades 27 and 28. A cartridge 33 is peripherally disposed in the shell 10 to extend from the blades 27-28 to the inner end of outlet tube 15. At what may be considered its outer end, the cartridge is cup shaped to be in substantially closely surrounding relation to tube 15. At its opposite or open end, the cartridge is tapered and engages over the tips of blades 31 and 32 in a manner to be in closely confining relation thereto. The cartridge 33 is comprised in the main of a synthetic fibrous or like material 34 held to a unitary form by encasing screening 35. The material 34 acts as a fibrous wick, absorbing liquid and serving as a transport media, by which the liquid may be conducted to a relatively small diameter shell outlet opening 36. A boss 37 is mounted to the side of the shell in surrounding relation to opening 36 and may be suitably connected to drain.

In the operation of the separator, air under pressure, entraining liquid in fog form is introduced into the separator through inlet tube 12. Passing over the sharp edge 13 of the inner end of tube 12, the air expands outward in shell imparting a momentum to entrained liquid to direct it to the inner wall of the shell and to the surfaces of blades 29 on member 23. Encounterin member 23, the air and entrained liquid flows past this air flow control member and in the process is given a rotary turning impulse of relatively low intensity. Continuing on in the separator, the air stream encounters members 27 and 28 and blades 31-32 of greater pitch. The air stream is at this location, therefore, given another and greater turning impulse. The helical, relatively restricted flow path of the air stream through the shell 10 increases its velocity and produces centrifugal influences which, together with impacting influences resulting from the water vapor striking the blade surfaces produces an agglomerating action whereby the finely divided vapor particles condense as droplets upon the inner surface of the shell or upon screen 35. In either event, the droplets are absorbed into the fibrous material 34 and transported thereby to outlet opening 36. Pressure difference across the opening 36 assists in maintaining a flow of liquid to drain fitting 37. The dried air continues its path through the shell 10, leaving the separator by way of outlet tube 15.

The bladed structure of air flow control members 23, 27 and 28 is such as to provide a cascade vane arrangement. Turning moments are imparted to the air stream with little pressure drop and a substantial blade area is provided for impacting of water vapors. The planned radial acceleration, due to the aerodynamic shape of the blades acting as air-foils produces flow through the separator without turbulence and without undue confinement of the moving fluid, both of which may increase resistance and consequently pressure loss. Further, the arrangement imposes no obstruction to a free flow through the separator under all conditions of operation. Clogging or icing cannot obstruct flow, an open path is at all times available from inlet tube 12 to outlet tube 15. Cartridge 33 may be removed as a unit, following prior removal of the sub-assembly comprising outlet tube 15, support 17 and ring 18, for cleaning or replacement. While turning or cascade vanes have been shown in two longitudinally spaced locations within the separator, it will be evident that a greater or lesser number of blade locations may be used in a device of this class, in accordance with the amount of air flow to be handled, the desired degree of efficiency and similar variables.

It may at times be necessary to introduce the air stream into the separator shell at an angle rather than in the axis thereof as shown in FIG. 1. It may be desirable under such a condition to maintain the concept of introducing the air into the separator through a sharp edged orifice. As shown in FIG. 4, a shell 38 has a first stage vane member 39 installed therein, with inlet of the moisture laden air to the shell being by way of a right angle duct 41. The inlet end of the shell is in this instance closed by means including a deflector plate 42, directing incoming air from duct 41 longitudinally of the shell 38 toward turning vane 39. Interposed between the deflector surface 42 and turning vane 39 is a plate 43 in which is a sharp edged opening 44 of a diameter less than the inner diameter of shell 38. Opening 44 is in the axis of shell 38 concentric with vane 39 and serves a purpose in bringing about a rapid, controlled expansion of the incoming fluid in the manner discussed in connection with sharp edged surface 13 in the FIG. 1 embodiment.

What is claimed is:

1. A device for removing entrained finely divided liquid particles from a flowing gaseous fluid under conditions of low pressure drop requirement, including a tubular shell having inlet and outlet openings at opposite ends thereof, a plurality of spaced apart cascade air-foils fixed in said shell and successively encountered by the flowing fluid to impart separated rotary turning impulses to the flowing fluid as it passes through the shell from said inlet to said outlet, each said air-foil having a greater pitch than the one preceding it, means peripherally installed in said shell beyond said air-foils absorbing liquid droplets agglomerated by created centrifugal, impacting and other influences, and means to drain absorbed liquid from the shell.

2. A device according to claim 1, characterized in that said last named means includes a small diameter opening in said shell to utilize pressure difference between the interior and exterior of the shell in the said draining of absorbed liquid.

3. A device according to claim 1, characterized in that said spaced apart air-foils are fixed in said shell at longitudinally spaced locations, those at a location nearer said inlet having a lesser pitch relative to the axis of the shell than those at a more distant location.

4. A device according to claim 1, characterized in that said spaced apart air-foils include at each of plural spaced apart locations a series of circumferentially spaced apart non-overlapping blades angularly disposed to impart a turning moment to the flowing fluid while allowing flow between the blades, the blades at each successively encountered location having a progressively greater pitch relative to the shell axis than blades at the immediately preceding location.

5. A device according to claim 4, characterized in that said inlet has the character of a sharp edged opening smaller in diameter than the diameter of said series of blades, incoming fluid expanding into contact with said blades.

6. A device according to claim 1, characterized in that said inlet opening is aligned with the axis of said shell and has a diameter less than the diameter of said shell, said opening terminating in sharp edged communication with the shell interior, said longitudinally spaced air-foils including a first set longitudinally spaced from said inlet opening and having a diameter corresponding approximately to the interior diameter of said shell, incoming fluid expanding into contact with said airfoils.

7. A device according to claim 1, characterized in that said air-foils comprise spaced apart sets of foils, a first set of which is positioned concentrically of the shell in adjacent relation to the inlet opening to be encountered thereby and give a turning moment to the flowing fluid, another set being disposed in the shell downstream of said first set with respect to the direction of flow of the fluid and being constructed to impart a turning moment to the fluid greater than the moment applied by the first set, said absorbing means being disposed as a cartridge to extend substantially from said second set of air-foils to the outlet end of the shell.

8. A device according to claim 1, characterized in that said cascade air-foils are comprised in first and second series, each series being composed of circumferentially spaced apart relatively narrow blades concentric in said shell and having a pitch relative to the shell axis to give a rotary impulse to fluid flowing past said blades, said first and second series of air-foils being located to be successively encountered by the flowing fluid and the blades thereof having a differential pitch so that the rotary impulse given the flowing fluid by said first series is less than that given by said second series, said air-foil blades achieving effective deflection of the flowing fluid in stages with minimum pressure drop.

9. A device for removing entrained finely divided liquid particles from a flowing gaseous fluid under conditions of low pressure drop requirement, including a tubular shell having an inlet at one end and an outlet at the opposite end, said inlet including means defining an opening aligned with the shell axis and having a diameter less than the diameter of said shell, said opening terminating in sharp edged communication with the shell interior, a circumferential series of air-foils stationarily installed in said shell in aligned facing relation to said opening and having a diameter exceeding the diameter of said opening whereby incoming fluid expands into contact with said air-foils and is given a rotary turning impulse thereby as it flows past said air-foils toward the opposite end of said shell, said air-foils being comprised in a series of circumferentially spaced apart non-overlapping blades disposing angularly of the shell axis, a cartridge including fibrous liquid transport material peripherally installed in said shell to extend beyond said air-foils toward the said opposite end of the shell, said material receiving agglomerated liquid droplets from the flowing fluid, and a small diameter opening in said shell in an area covered by said cartridge to which liquid is transported by said material and utilizing pressure difference between the interior and exterior of the shell in the draining of liquid.

10. A device according to claim 9, characterized by a second circumferential series of air-foils fixed in said shell in concentric longitudinally spaced relation to the first said series, the second said series being subsequently encountered by the flowing fluid and being composed of plural sets of blades having a common pitch which is greater than the pitch of the blades of the first said series, adjacent sets of blades of said second series being angularly displaced relatively to one another.

References Cited UNITED STATES PATENTS 1,215,935 2/1917 Hickman 55-457 X 2,087,789 7/1937 Allardice -2 55454 X 2,232,913 2/1941 Heuberger 55457 X 2,659,450 11/1953 Baird 55456 X 2,709,501 5/1955 Toth et a1. 55450 2,773,598 12/1956 Castellani 55456 X 2,961,064 11/1960 Fisher 55-457 2,970,669 2/1961 Bergson 55269 3,216,182 11/1965 Cochran et al 55448 X 3,372,532 3/1968 Campbell 55-455 X FOREIGN PATENTS 1,102,737 5/ 1955 France.

555,908 9/1943 Great Britain.

HARRY B. THORNTON, Primary Examiner D. E. TALBERT, JR., Assistant Examiner US. Cl. X.R. 55457 

